wernicke's area

aphasia

glial cells

supportive cells of the nervous system that guide the growth of developing neurons. They help provide nutrition for and get rid of wastes of neurons. Also forma an insulating sheath around neurons that speeds conduction.

neurotransmitters

acetylcholine

a neurotransmitter that causes contraction of skeletal muscles, helps regulate heart muscles, is involved in memory and also transmits messages between the brain and spinal cord. lack of this is associated with alzheimer's disease.

action potential

all-or-none principle

that law that the neurons either generates an action potential when the stimulated reaches a threshold or doesn't fire when stimulation is below threshold. the strength of the action potential is constant whenever it occurs

nodes of ranvier

saltatory conduction

synapse

region of communication between the transmitting presynaptic neuron and receiving postsynaptic neuron, muscles, or gland, consisting of the presynaptic terminal buttons, a tiny space and receptor sites typically on the postsynaptic dendrites

afferent neuron

interneuron

nerve cell int eh CNS that transmits impulses between sensory and motor neurons. neural impulses travel one way along the neuron from dendrites to axons to terminal buttons, and among neurons from the receptor to the effector.